Astronomy clicker question: Charon

Astronomy 10, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Astronomy 10 learning goal M2.5

Students were asked the following clicker question (Classroom Performance System, einstruction.com) at the end of their learning cycle, during a review session just before the midterm. Students are encouraged to collaborate openly, as their review session clicker points for responding will double if the cumulative class success rate is at or over 80% (out of 10 questions).

[0.3 points.] Which one of the following choices best explains why Charon is neither categorized as a planet, nor a dwarf planet under the new International Astronomical Union rules?
(A) Charon is one of Pluto's three satellites.
(B) Charon did not clear its orbit of other Kuiper belt objects.
(C) Charon is the remnant of a giant impact on Pluto that produced icy debris that made the Kuiper belt.
(D) Charon is not spherical in shape.
(E) Charon is mainly composed of ice.

Correct answer: (A).

Student responses
Section 4136
(A) : 30 students
(B) : 0 students
(C) : 0 students
(D) : 2 students
(E) : 0 students

Section 5076
(A) : 20 students
(B) : 0 students
(C) : 1 student
(D) : 7 students
(E) : 0 students

So far, so good. Let's see how they did during the midterm...